Codex Knowledge Base
GitHub Copilot CLI Agent vs Codex CLI: Same Model, Different Harness — Two Terminal Agents Compared
On 17 May 2026, GitHub quietly switched the default model for Copilot Business and Enterprise users to GPT-5.3-Codex — the same model that powers OpenAI's.
Gemini 3.5 Flash vs GPT-5.5 and codex-mini: Coding Model Benchmark Comparison After Google I/O 2026
Google I/O 2026 dropped Gemini 3.5 Flash on 19 May with a bold claim: it beats Gemini 3.1 Pro on coding benchmarks whilst running four times faster than.
Detached Subagent Patterns for Codex CLI: Context-Free Orchestration Beyond Built-in Fork Semantics
Codex CLI's built-in subagent system uses fork semantics: child agents inherit the parent's context window, sandbox policy, and runtime overrides .
codex doctor: The Diagnostics Command That Replaces Manual Log Archaeology
Before Codex CLI v0.131.0, diagnosing a broken installation meant spelunking through ~/.codex/log/codex-tui.log, manually inspecting auth.json token expiry.
Codex CLI v0.132.0 Release Guide: Python SDK Authentication, exec resume --output-schema, and Performance Gains
Codex CLI v0.132.0 shipped on 20 May 2026 with a release that prioritises two themes: making the Python SDK a proper first-class citizen for programmatic.
Codex CLI's SDK Maturation Arc: How v0.130–v0.132 Turned a Terminal Tool into a Programmable Agent Platform
Three releases in twelve days. Between 8 May and 20 May 2026, Codex CLI shipped v0.130, v0.131, and v0.132 — and each one quietly pushed the project further.
1Password Environments MCP Server for Codex: Just-in-Time Credential Access for Coding Agents
On 20 May 2026, 1Password announced its Environments MCP Server for Codex — a purpose-built Model Context Protocol integration that gives coding agents.
RTK and Codex CLI: Killing Token Waste at the Shell Boundary
Run git log --oneline -20 in a Codex CLI session and watch what happens. Twenty commit hashes, twenty author names, twenty dates, twenty subject lines.
OpenAI's Unified Agentic Platform: What the ChatGPT-Codex Merger Means for CLI Developers
On 16 May 2026, OpenAI co-founder and president Greg Brockman circulated an internal memo confirming that ChatGPT, Codex.
Migrating from Gemini CLI to Codex CLI: A Practical Guide After the Antigravity Transition
Google announced the Gemini CLI to Antigravity CLI transition at Google I/O on 19 May 2026 .